2,898 research outputs found

    The effect of mark enhancement techniques on the subsequent detection of saliva

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    There appears to be a limited but growing body of research on the sequential analysis/treatment of multiple types of evidence. The development of an integrated forensic approach is necessary to maximise evidence recovery and to ensure that a particular treatment is not detrimental to other types of evidence. This study aims to assess the effect of latent and blood mark enhancement techniques (e.g. fluorescence, ninhydrin, acid violet 17, black iron-oxide powder suspension) on the subsequent detection of saliva. Saliva detection was performed by means of a presumptive test (Phadebas®) in addition to analysis by a rapid stain identification (RSID) kit test and confirmatory DNA testing. Additional variables included a saliva depletion series and a number of different substrates with varying porosities as well as different ageing periods. Examination and photography under white light and fluorescence was carried out prior to and after chemical enhancement All enhancement techniques (except Bluestar® Forensic Magnum luminol) employed in this study resulted in an improved visualisation of the saliva stains, although the inherent fluorescence of saliva was sometimes blocked after chemical treatment. The use of protein stains was, in general, detrimental to the detection of saliva. Positive results were less pronounced after the use of black iron-oxide powder suspension, cyanoacrylate fuming followed by BY40 and ninhydrin when compared to the respective positive controls. The application of Bluestar® Forensic Magnum luminol and black magnetic powder proved to be the least detrimental, with no significant difference between the test results and the positive controls. The use of non-destructive fluorescence examination provided good visualisation; however, only the first few marks in the depletion were observed. Of the samples selected for DNA analysis only depletion 1 samples contained sufficient DNA quantity for further processing using standard methodology. The 28 day delay between sample deposition and collection resulted in a 5-fold reduction in the amount of useable DNA. When sufficient DNA quantities were recovered, enhancement techniques did not have a detrimental effect on the ability to generate DNA profiles. This study aims to contribute to a strategy for maximising evidence recovery and efficiency for the detection of latent marks and saliva. The results demonstrate that most of the enhancement techniques employed in this study were not detrimental to the subsequent detection of saliva by means of presumptive, confirmative and DNA tests

    Teasing apart fine- and coarse-scale effects of environmental heterogeneity on tree species richness in Europe

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    The environmental heterogeneity–biodiversity relationship is generally hypothesised to be positive, with greater heterogeneity leading to greater biodiversity. However, the generality of positive environmental heterogeneity–species richness relationships is often debated, with some studies finding non-significant or even negative relationships. Negative relationships have primarily been found at fine spatial scales. Both negative and positive relationships have a basis in ecological theory. Environmental heterogeneity at coarse scales opens up niche space to allow more species to coexist; whereas high local heterogeneity, for instance in topography, may lead to increased local extinction due to micro-fragmentation, or dominance of species suited to heterogeneous conditions. However, it is difficult to attribute how much of the variance is explained at different scales within the same modelling framework.Here, we use a new data-aggregation method which enables us to include both fine- and coarse-scale environmental heterogeneity within the same analysis. Using this method, we were able to tease apart the fine- and coarse-grain effects of topographic heterogeneity on European tree species richness. At the coarse scale (0.5 degrees), we found a positive effect of range in elevation on tree species richness. However, when measuring range in elevation using a fine-scale moving window of radius 500 m, we found a negative relationship with tree species richness. This supports existing research that has shown negative relationships between environmental heterogeneity and species richness at finer spatial grains. Because we were able to include a measure of both local and landscape-scale topographic heterogeneity in the same model, for the first time we could fully capture the effects of both scales on coarse-grain species richness while accounting for the effect of the other scale

    The percutaneous absorption of soman in a damaged skin porcine model and the evaluation of WoundStatâ„¢ as a topical decontaminant

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    PURPOSE: The aim of this study was to evaluate a candidate haemostat (WoundStat™), down-selected from previous in vitro studies, for efficacy as a potential skin decontaminant against the chemical warfare agent pinacoyl methylfluorophosphonate (Soman, GD) using an in vivo pig model. MATERIALS AND METHODS: An area of approximately 3 cm2 was dermatomed from the dorsal ear skin to a nominal depth of 100 µm. A discrete droplet of 14C-GD (300 µg kg-1) was applied directly onto the surface of the damaged skin at the centre of the dosing site. Animals assigned to the treatment group were given a 2 g application of WoundStat™ 30 s after GD challenge. The decontamination efficacy of WoundStat™ against GD was measured by the direct quantification of the distribution of 14C-GD, as well as routine determination of whole blood cholinesterase and physiological measurements. RESULTS: WoundStat™ sequestered approximately 70% of the applied 14C-GD. Internal radiolabel recovery from treated animals was approximately 1% of the initially applied dose. Whole blood cholinesterase levels decreased to less than 10% of the original value by 15 min post WoundStat™ treatment and gradually decreased until the onset of apnoea or until euthanasia. All treated animals showed signs of GD intoxication that could be grouped into early (mastication, fasciculations and tremor), intermediate (miosis, salivation and nasal secretions) and late onset (lacrimation, body spasm and apnoea) effects. Two of the six WoundStat™ treated animals survived the study duration. CONCLUSIONS: The current study has shown that the use of WoundStat™ as a decontaminant on damaged pig ear skin was unable to fully protect against GD toxicity. Importantly, the findings indicate that the use of WoundStat™ in GD contaminated wounds would not exacerbate GD toxicity. These data suggest that absorbent haemostatic products may offer some limited functionality as wound decontaminants.Peer reviewedFinal Accepted Versio

    Abnormal long wave dispersion phenomena in a slightly compressible elastic plate with non-classical boundary conditions

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    A two parameter asymptotic analysis is employed to investigate some unusual long wave dispersion phenomena in respect of symmetric motion in a nearly incompressible elastic plate. The plate is not subject to the usual classical traction free boundary conditions, but rather has its faces fixed, precluding any displacement on the boundary. The abnormal long wave behaviour results in the derivation of non-local approximations for symmetric motion, giving frequency as a function of wave number. Motivated by these approximations, the asymptotic forms of displacement components established and long wave asymptotic integration is carried out

    Simultaneous real-time visible and infrared video with single-pixel detectors

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    Conventional cameras rely upon a pixelated sensor to provide spatial resolution. An alternative approach replaces the sensor with a pixelated transmission mask encoded with a series of binary patterns. Combining knowledge of the series of patterns and the associated filtered intensities, measured by single-pixel detectors, allows an image to be deduced through data inversion. In this work we extend the concept of a ‘single-pixel camera’ to provide continuous real-time video at 10 Hz , simultaneously in the visible and short-wave infrared, using an efficient computer algorithm. We demonstrate our camera for imaging through smoke, through a tinted screen, whilst performing compressive sampling and recovering high-resolution detail by arbitrarily controlling the pixel-binning of the masks. We anticipate real-time single-pixel video cameras to have considerable importance where pixelated sensors are limited, allowing for low-cost, non-visible imaging systems in applications such as night-vision, gas sensing and medical diagnostics

    Magnetic switching modes for exchange spring systems ErFe2/YFe2/DyFe2/YFe2 with competing anisotropies

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    The magnetization reversal processes of ½10nm ErFe2=nYFe2=4nm DyFe2=nYFe2" multilayer films with a (110) growth axis and a variable YFe2 layer thickness n are investigated. The magnetically soft YFe2 compound acts as a separator between the hard rare earth (RE) ErFe2 and DyFe2 compounds, each of them bearing different temperature dependent magnetic anisotropy properties. Magnetic measurements of a system with n ¼ 20nm reveal the existence of three switching modes: an independent switching mode at low temperatures, an ErFe2 spin flop switching mode at medium high temperatures, and an YFe2 dominated switching mode at high temperatures. The measurements are in qualitative agreement with the findings of micromagnetic simulations which are used to illustrate the switching modes. Further simulations for a varied YFe2 layer thickness n ranging from 2 to 40nm are carried out. Quantitative criteria are defined to classify the reversal behavior, and the resultant switching modes are laid out in a map with regard to n and the temperature T. A new coupled switching mode emerges above a threshold temperature for samples with thin YFe2 separation layers as a consequence of the exchange coupling between the magnetically hard ErFe2 and DyFe2 layers. It reflects the increasing competition of the two conflicting anisotropies to dominate the magnetic switching states of both RE compounds under decreasing n

    Which anthropometric and lower body power variables are predictive of professional and amateur playing status in male rugby union players?

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    The purpose of this study was to compare anthropometric and lower body power measurements between current professional and amateur male rugby union players. The present study also sought to determine which anthropometric and physical performance variables were predictive of playing standard. Thirty professional and 30 amateur RU players performed Wattbike 6 s maximal effort (WB6S) and countermovement (CMJ) and squat jump (SJ) assessments, anthropometric measures were also taken. Dependant variables recorded and analysed including: body mass, stature, Σ8 site skinfolds, WB6S absolute and relative peak power, CMJ and SJ average concentric force, jump height, peak velocity, time to peak force, rate of force development (RFD) and absolute and relative peak force and power. Professional players were heavier, taller and leaner than their amateur counterparts (p < 0.05). Professional players performed significantly better in all physical performance measures except CMJ and SJ time to peak force, CMJ RFD and SJ relative peak force. Variables which were predictive of playing standard were: Σ8 skinfolds, CMJ peak velocity and WB6S absolute and relative peak power (p < 0.05). These findings indicate that the current body of male professional RU players is anthropometrically and physically superior to their amateur counterparts, although not all variables assessed here were predictive of playing standard. Data presented here indicate that Σ8 skinfolds, WB6S absolute and relative power and CMJ peak velocity are predictive of playing standard, whereas other anthropometric and strength and power variables are not

    Annual Survey of Virginia Law: Environmental Law

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    Recent developments in environmental law in Virginia continue to reflect several trends. These trends may be grouped into six general categories: (1) the growing tension between federal environmental mandates and their practical implementation through delegated state programs; (2) the continuing debate over the exact definition of interstate commerce and the scope of state authority to regulate in the gray area; (3) the impending deregulation of the electrical energy market; (4) the promotion of sustainable development; (5) the developing schism between state and local land use control; and (6) the evolving nature of administrative law in the environmental context. The following survey discusses changes to the body of environmental law affecting Virginians during 2000-2001 in the context of each of these trends
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